csci-351 - taejoong (tijay) chung...dnssec 101 13.com example.com 1.2.3.4 rrsig dnskey chain of...

CSCI-351  Data communication and Networks

Lecture 16: PKI + DNSSEC Warning: This may be hard to understand. Do not lose yourself during the class and keep asking questions

Project 4 Released

• DNSSEC Client

Final Schedule

• 8:00am — 10:30am at December 13th

• Comprehensive

Project 3Title

Scor

es

0

0.25

0.5

0.75

1

Category Axis

Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)Score ( 1 == FULL POINT)

Score ( 1 == FULL POINT)

Will send you the feedbacks of Project 2 and 3 by the next class

Please

Public Key Cryptography

Encryption

Public

Private

Alice

Authentication

Alice

6

Public Key Infrastructure

How can I trust this key?

PKIPublic Key Infrastructure (PKI) supports the (1) distribution and (2) identification of public key

….

7

Hierarchical Public Key Infrastructure

I only trust this key(s)

Trust Anchor(s)

HierarchicalPKI

Many secure protocols in the Internet rely on hierarchical PKI

Oh. now I trust your keyChain of trust

8

Something to plug (1)New course – Spring 2019

• I’ll be teaching a new (Graduate-Level) Seminar Course in the Spring 2019• GCCIS-CSCI-759 Topics In System• Title: Public Key Infrastructure and Network Security

• Security is really important! (who doesn’t say..)

9

Again, Signing and verification process

10

Data

Hashed Data(Digest)

Hash function (e.g., SHA256)

Data

Decrypted Digest

Signature(Encrypted Digest)

Signature(Encrypted Digest)

Hashed Data(Digest)


Public

PrivateSender Receiver Public

Same or not?

Domain Name System (DNS)

example.com'sAuthoritativeDNS Server

Browser

11

DNS Resolver

example.com example.com

A records*

155.33.17.68

A records

155.33.17.68

*A record: one of the DNS records that contains IP addresses of a domain name

DNS Spoofing


Browser

12

DNS Resolver

example.com example.com

A recordsA records

1.2.3.4 155.33.17.68✗1.2.3.4Advertisement or other contents

. (root)

DNS Resolverexample.com'sAuthoritativeDNS Server

DNSSEC 101

13

.com

example.com

1.2.3.4 RRSIG

DNSKEY

Chain of Trust

. (root)


DNSSEC 101

14

.com

= Hash( )4c04a5 … ff0cdd

DNSSEC 101: Hierarchy Builds Trust

15

DS Record

RRSIG


.com

DS Record

16

DS Record


.comRRSIG

DNS ResolverDNSKEY

DS Record

DNSKEY

compare!

DNSSEC 101: Hierarchy Builds Trust

DNSSEC: Hierarchical PKI

I only trust this key

Root DNSKEY

example.com

17

.com

. (root) DS Record

DS Record

Signing and verification process in DNSSEC

18

DNS Records (RRSets)

Hash of DNS Records


DNS Records (RRSets)

Hash of DNS Records

Signature (RRSIG)

Signature (RRSIG)

Hash of DNS Records


Public

PrivateSender Receiver Public

Same or not?

Two DNSKEYs

19


A Record

Signature (RRSIG)


DS RecordDS Record

.com’sAuthoritativeDNS Server

DS Record

Two DNSKEYs

20

A Record

Signature (RRSIG)

.com’sAuthoritativeDNS Server

DS Record


Key Signing Key (KSK)

Zone Signing Key (ZSK)

ZSK

RRSIG of ZSK


DS RecordDS Record

Two DNSKEYsAre you serious? Why?

21

Frequently used to generate signatures for the DNS

records=> should be loaded on the memory

=> Not secure

Only used to generate the signature of “ZSK”

=> Not heavily used=> Stored in the offline storage

(e.g., HSM)=> More secure!


Key Signing Key (KSK)

Zone Signing Key (ZSK)

Revisiting 3 Principles of Information Security

• Confidentiality• Integrity• Availability

22

Motivation of this research

23

Even though DNSSEC was introduced 20 years ago!

Research Questions

24

If it is not managed well, then why?

How can we improve it?

How well is today’s DNSSEC PKI ecosystem managed?

How to Deploy DNSSEC (Correctly)

25

DNSKEY (1) Have DNSKEYs

RRSIGs (2) Generate Signatures

DS record Uploads

(3) Generate and upload DS record  to the parent zone

Scanning All Domains

26

Daily Scans

TLDs .com, .org., .net

# of domains 147M domains

Interval every day

Period 2015/03/01 ~ 2016/12/31

Over 750 billion DNS Records

0

0.2

0.4

0.6

0.8

1

1.2

02/15 05/15 08/15 11/15 02/16 05/16 08/16 11/16

Perc

en

t o

f d

om

ain

s w

ith

DNSKEY

re

co

rd

Date

.com

.net

.org

How DNSSEC is deployed

27

Deployment DNSSEC deployment is rare, but growing

DNSKEY

RRSIGs

DS record Uploads

RRSIGs

~1.0%

Generating Signatures

28

~0.3%

Missing RRSIGs RRSIGs are rarely missing (0.3%)

0

0.5

1

1.5

2

2.5

02/15 05/15 08/15 11/15 02/16 05/16 08/16 11/16

missing SOA RRSIGmissing DNSKEY RRSIG

Perc

en

t o

f d

om

ain

sm

issin

g RRSIG

s

.com

.net

.org

~1.0%DNSKEY

RRSIGs

DS record Uploads

RRSIGs

Building a Chain of Trust

29

~0.3%

~30%

0

5

10

15

20

25

30

35

02/15 05/15 08/15 11/15 02/16 05/16 08/16 11/16Pe

rce

nt

of

do

ma

ins

mis

sin

gDS

re

co

rd

.com

.net

.org

DS Records

Nearly 30% of domains DO NOTupload DS records!

~1.0%DNSKEY

RRSIGs

DS record Uploads

RRSIGs

Why does DNSSEC deployment remain so small? Why are 30% of domains w/o DS records?

Deploying a DNSSEC on Your Server

30

.COM (Verisign)

Registry (TLD)

GoDaddyRegistrar OwnerBuy

example.comDS

RecordDS

Record

I need a domain

Third Party DNS Operator

31

Deleg

ate

CloudFlareThird-Party DNS Operator

.COM (Verisign)

GoDaddy

Registry (TLD)

Registrar

Buy

example.com

DS Record

Third Party DNS Operator

32

Deleg

ate

CloudFlareThird-Party DNS Operator

.COM (Verisign)

GoDaddy

Registry (TLD)

Registrar

Buy

example.com

Reseller

33

Deleg

ate

CloudFlareThird-Party

DNS Operator

.COM (Verisign)

ASCIO

Registry (TLD)

Registrar

Buy

example.comAntagonistReseller

DS Record

Checking Registrar’s DNSSEC Policy

34

Registrar DNS Operator

Registrar Supports DNSSEC?

Owner DNS Operator

Registrar Supports

DS upload?

RegistrarValidates

DS record?

Popular Registrar’s DNSSEC Policy

35

Registrar(Authoritative Nameserver)

GoDaddy (domaincontrol.com)

NameCheap (registrar-servers.com)

OVH (ovh.net)

HostGator (hostgator.com)

Amazon (aws-dns)

Google (googledomains.com)

123-reg (123-reg.co.uk)

RightSide (name.com)

eNom (name-services.com)

NameBright (namebrightdns.com)

DreamHost (dreamhost.com)

The others (10 registrars)

Registrar DNS

Operator

Some nameservers don’t support DNSSEC


Registrar Supports

DS upload?

RegistrarValidates

DS record?

3/20

Anecdotal Examples

36

We saw the DNSKEY deployed (but not DS records) so asked why you don’t upload DS records.

[1] They removed a DNSSEC menu

We asked a registrar to upload a DS record to our domain via web live chat

It was installed on someone else’s domain due to a mistake by the customer service agent

We asked a registrar to upload a DS record by email from the different email address than the one that registered

It was installed successfully

Experiment Result

[2] “Most people do not understand DNS, so imagine the white faces when I mention DNSSEC”

Details of the Last Example

37

3:45:32 PM tijay hg-dnssec.com 3600 IN DS 2371 13 2 129f34c04ac58ece5218b9894148304a736a63757f58ff0cddd9b8df4989

3:56:09 PM Jeniffer S I have now save the request information! Manage DNSSEC paananenmusic.com Record added successfully. It can take 4-8 hours for DNS to propagate3:57:19 PM tijay paananenmusic.com?3:57:28 PM tijay my domain is hg-dnssec.com?

3:58:41 PM Jeniffer S I apologize, you are right, silly me, one moment

3:56:05 PM Jeniffer S Awesome! one moment


38

Owner DNS Operator DS Upload

Web Email

————————




OVH (ovh.net)


Amazon (aws-dns)









Registrar Supports

DS upload?

RegistrarValidates

DS record?

3/20

11/20


39

DS Validation




OVH (ovh.net)


Amazon (aws-dns)








Owner DNS Operator DS Upload

Web Email

————————


Registrar Supports

DS upload?

RegistrarValidates

DS record?

2/20

3/20

11/20

Summary: Registrar’s DNSSEC Support

40

DNS Operator

# of Registrar

Support DNSSEC?

Registrar 3/20

Owner 11/20

What this means to you

If you don’t want to run your own name server, most of the time, you CAN’T deploy DNSSEC (17/20)

If you do want run your own nameserver, still you CAN’T deploy

DNSSEC for 9/20

Check DS Validation Owner 2/11

If you happen to upload an incorrect DS record, your domain will be

inaccessible

Why are DNSSEC support of registrars so rare?

Cost of Managements

41

DNS DNSSEC

# of RecordsDNSSEC introduces much more records

(e.g., need signatures for each record)

Size of Records Signatures are usually 3~6 times larger than non-DNSSEC records*

Management -Strong KeyUnique Key

Rollover

Operational Cost

Operational cost of DNSSEC is higher than that of DNS

*DNSSEC and Its Potential for DDoS Attacks (IMC’14)

Case Study: Registrar’s Policy

42

Registrar DNS Operator

Owner DNS Operator

Support DNSSEC Pricing

Support DNSSEC Pricing

# of registrars 3Free: 2

11 FreePaid: 1

Registrars manage all DNS records

Registrars DO NOT need to manage DNS records at all

Scanning All Domains

43

TLDMeasurement Period

(Daily Scan)

Domains

Total Percent w/ DNSKEY

.com 2015/03/01 ~ 2016/12/31 118,147,199 0.7%

.net 2015/03/01 ~ 2016/12/31 13,773,903 1.0%

.org 2015/03/01 ~ 2016/12/31 9,682,750 1.1%

.nl 2016/02/09 ~ 2016/12/31 5,674,208 51.6%

.se 2016/06/07 ~ 2016/12/31 1,388,372 46.7%

0

20

40

60

80

100

05/15 08/15 11/15 02/16 05/16 08/16 11/16

Loopia (*.loopia.se)

Pe

rce

nt

of

do

ma

ins

wit

h DNSKEY

an

d DS

rec

ord

Date

.com

.net

.org.se.nl

0

20

40

60

80

100

KPN (*.is.nl)

.com

.net

.org.se.nl

Case Study: Financial Incentives

44

KPN

Financial Incentive

Financial gain is a huge incentive  for deploying DNSSEC

.nl measurement begins here

.se measurement begins here

Loopia

to certain domains

DNSSEC Resolvers

45

Correct Deploymentfor Resolvers

46

DO Bit (1) DNSSEC OK bit in the header

Validation (2) Validate DNSSEC Records

Measuring DNS resolver

47

Comcast Network

DNS Resolver

Authoritative DNS Server

MeasurementNode

Client

Ads

No Control over the nodeNot Reproducible

NENS’2016

Hola Unblocker

Luminati

49

MeasurementNode

Local DNSResolver

Proxy

Comcast

Residential Authoritative DNS Server

AT&T

Rogers

Deutsche Telekom

Verizon

Control over the nodeReproducible

Scales

Node

NENS’2016

Get bostonglobe.com

Measurement ClientSuper ProxyExit Node

Exit Node’s DNS Server

HTTP

DNS

Luminati

51

Local DNSResolver

Authoritative DNS ServerNode

MeasurementNode

Comcast

Residential

Control over the nodeReproducible

Scales

Methodology

52

Local DNSResolver

Authoritative DNS Server

(Our testbed)

A records

w/ DO bit

RRSIG

A records

+ 8 other scenarios of  incorrect DNSSEC records

Resolvers w/ DO Bit

53

DO Bit

Validation

- 4,427 resolvers- 83% of them are DO-bit enabled

Resolvers w/ DO Bit

54

DO Bit

Validation

- 3,635 (82%) fail to validate DNSSEC records

- 543 (12.2%) correctly validate  DNSSEC records

Time Warner Cable InternetRogers Cable Communications

ComcastGoogle

- 4,427 resolvers- 83% of them are DO-bit enabled

Open Resolver Tests

55

Provide DO Bit Requested Validated?DS DNSKEY

Verisign YES YES YES YESGoogle YES YES YES YESDNSWatch YES YES YES YESDNS Advantage YES YES YES YESNorton ConnectSafe YES YES YES YESLevel3 YES NO NO NOComodo Secure DNS YES NO NO NOSafeDNS YES NO NO NODyn YES NO NO NOGreenTeamDNS* YES/NO YES YES NOOpenDNS NO NO NO NOOpenNIC NO NO NO NOFreeDNS NO NO NO NOAlternate DNS NO NO NO NOYandex DNS NO NO NO NO

csci-351 - taejoong (tijay) chung...dnssec 101 13.com example.com 1.2.3.4 rrsig dnskey chain of...

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